class_docstr: Feature cache manager for cache sharing between different cost models
docstr: Clear feature cache for a key
  
  Parameters
  ----------
  key: str
      The key of a feature type
docstr_tok: ["Clear","feature","cache","for","a","key","Parameters","--","--","--","--","--","key",":","str","The","key","of","a","feature","type"]
code: def clear(self, key):
      """Clear feature cache for a key
  
      Parameters
      ----------
      key: str
          The key of a feature type
      """
      del self.feature_cache[key]
      self.feature_cache[key] = {}
      gc.collect()
  
imports: import gc
  import numpy
  from .tuner import Tuner
  from ..env import GLOBAL_SCOPE
label_desc: Use image node_id 4 for calling the FeatureCache obj's underlying member method code with example usage: obj.clear(key) without return types